Efficient cooperative OFMD localization

Abstract

The author of this project has been working on the topic of cooperative OFDM localization for one year in the TU Delft as an exchange student. Nowadays there are many potential uses for cooperative localization in places in which the common systems like GPS could not provide an accurate estimation. It is an advantage to join into a wireless network with a mobile device and be able to navigate and know your position. Two critical points in this topic are the accuracy of the localization, that is required to be high, and the power consumption of the mobile devices, which is a critical resource. Existing indoor cooperative localization methods require big battery consumption for the mobile relays, and the accuracy in low SNR situations is not good enough. The scope of this thesis is to estimate the localization of an unknown mobile device in an efficient way, being accurate even in low SNR situations, with low power consumption. One first approximation and the reference [11] suggested the idea of the “feature method” which is a bandwidth efficient cooperative ZP-OFDM localization method. After testing different features and conclude that the peak to average power ratio has the best performance another new idea came up. A new simple relay is proposed, called trigger relay, which consists of forwarding a known signal when the incoming signal is received. With this new idea it is solved the bandwidth and computational problem, being the most efficient method to estimate the TDOA. This brilliant idea was published in the PIMRC conference in September, 2011.